Theory of Evolution:Darwin vs. Lamarck

Texas Horned LizardDefense Behavior Adaptations

-Its horns are extensions of its cranium and contain true bone.

-When threatened it will puff up its body to cause its spiny scales to protrude, which makes it hard to swallow.

-Has the ability to squirt an aimed stream of blood from the corners of it’s eyes and sometimes mouth for a distance up to 5 feet.

Objective

• Students will be able to identify three scenarios of Darwin and Lamarck’s theory of evolution on a worksheet provided in class.

Venn Diagram

Different DifferentSame

Who is Darwin and Lamarck?Charles Darwin

• Feb. 1809-April 1882• English Naturalist.• Published his theory

of evolution in his book On the Origin of Species.

• Remembered for his theory of evolution called natural selection.

Jean-Baptiste Lamarck• Aug. 1744-Dec. 1829• French Naturalist.• Provided the first truly

cohesive theory of evolution.

• Remembered for his use/disuse theory of evolution.

Darwin’s Theory of Evolution

• Organisms that have variation will adapt to their environment and have more offspring.

• Offspring are born with their parents’ favorable traits and as they reproduce those traits become more dominant.

• Inheritance• Variation

Lamarck’s Theory of Evolution• Changes in an organism are influenced by

what the organism wants or needs and then over many generations the offspring are born with these changes.

• Individual structures (body parts) of an organism decreases in size by disuse and increases in size when used.

• Wants and Needs• Use and Disuse

Darwin and Lamarck agreed that…

• Organisms change to work better in their environment.

• Organisms have evolved (changed) over time and are still evolving.